It is common to treat the surface of a textile with a composition to make the textile oil repellent, water repellent and resistant to soil. Fluorochemical compositions are commercially available for this purpose. Various patents disclose a variety of such compositions.
For example, U.S. Pat. No. 2,803,615 (Ahlbrecht et al.) discloses a class of acrylate or methacrylate esters of N-alkyl, N-alkanol perfluoroalkanesulfonamides used to impart both repellency to water and resistance to absorption and soiling by oily and greasy materials. U.S. Pat. No. 3,236,672 (Shane et al.) discloses an oil and water repellent consisting of an alkylene imine compound and a perfluoro alkyl acrylate also useful to impart water and oil repellency.
Traditionally, the fluorochemical compositions used for oil and water repellency are dissolved in strong organic solvents. Chlorinated solvents such as trichloroethylene, perchloroethylene and 1,1,1 trichloroethane are used to dissolve fluorochemical compositions in U.S. Pat. No. 4,366,300 (Delescluse), U.S. Pat. No. 3,341,497 (Sherman) and U.S. Pat. No. 4,401,780 (Steel). However, due to the adverse effects of chlorinated hydrocarbons on the Earth's ozone layer, these solvents are no longer desirable.
Delescluse also teaches the use of strong carbonyl containing solvents such as ketones and esters used as solvents for fluorochemical compositions. The ketones disclosed by Delescluse include methylethylketone and the esters include ethyl acetate, butyl acetate and amyl acetate. These solvents are undesirable due to their toxicity and odor. In addition, these solvents can damage materials such a fabrics to which they contact. Damage can include dye bleed and even disintegration of the material.
Sherman teaches the use of a third class of solvents which are neither halogenated solvents nor strong carbonyl solvents. The solvents disclosed by Sherman include xylene. Aromatic solvents are undesirable because of their toxicity. In addition, Sherman uses these solvents in combination with a fluorochemical composition comprising: (1) about 2 to about 50 percent by weight of monomeric units of R.sub.f P where R.sub.f is a perfluorocarbon radical-containing at least 4 carbon atoms and P is a polymerizable group containing terminally ethylenic unsaturation, (2) about 1 to about 25 percent by weight of a monomer containing a functional grouping containing either amide, amine, urea or hydroxyl group reactable with formaldehyde and (3) about 25 to about 97 percent by weight of a terminally ethylenically unsaturated monomer free of active hydrogen and nonvinylic fluorine such as acrylic and esters thereof. A drawback associated with Sherman's fluorochemical composition is that it is insoluble in nonhalogenated solvents when it contains fluorine in amounts greater than 40 percent by weight.
Delescluse discloses yet another type of solvent, useful to dissolve fluorocarbon compositions. The fourth type of solvent comprises aliphatic hydrocarbons which include gasoline and white spirit. Delescluse teaches the use of this group of solvents in conjunction with a liquid composition comprising 89 to 99.5% by weight solvent, 0.1 to 1% by weight fluorinated resin and 0.4 to 10% by weight adjuvant. The adjuvants, which include thermoplastic resins, waxes and aminoplast resins based on melamine, are utilized by Delescluse as binder resins. Binder resins can be defined as substances used to distribute the fluorochemical composition throughout a coating and to afford adhesion to the substrate onto which the fluorochemical composition is applied.
Thus, there currently exists a need for a fluorochemical composition which does not utilize a binder resin in a hydrocarbon solvent system and which is soluble in a solvent system which is non-halogenated or substantially non-halogenated and which is substantially free of strong carbonyl solvents.